Insert for augmented reality viewing device

ABSTRACT

A visual perception device is described. The visual perception device has corrective optics for viewing virtual and real-world content. An insert for the corrective optics is attached using a magnetic set, pins and/or a nose piece. Interchangeable nose pieces allow for height adjustments to accommodate different users. The visual perception device has pliable components to absorb forces exerted on a nose piece and a protective barrier for limiting electric shock or ingress of dirt.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority from U.S. Provisional PatentApplication No. 62/608,054, filed on Dec. 20, 2017, all of which isincorporated herein by reference in its entirety.

BACKGROUND OF THE INVENTION 1). Field of the Invention

This invention relates to a visual perception device.

2). Discussion of Related Art

Modern computing and display technologies have facilitated developmentof visual perception devices such as “virtual reality” viewing devices.A virtual reality viewing device is a wearable device that presents theuser with two images, one for the left eye and one for the right eye.Objects in the images differ from one another in a manner that allowsthe brain to process the object as a three-dimensional object. When theimages constantly change, movement in three-dimensions can be simulated.A virtual reality viewing device typically involves presentation ofdigital or virtual image information without transparency to otherreal-world objects.

Other visual perception devices, so called “augmented reality” viewingdevices usually include technology that allows for the presentation ofdigital or virtual image information as an augmentation to visualizationof the actual world around the user.

Visual perception devices of the above kind often have a strap that fitsaround a head of a user or other structure that fits on the head of auser. These straps or structures are frequently adjustable to suit theuser. Other user-specific accommodations are usually not included insuch visual perception devices. For example, a user may requirecorrective optics in order to see an image that is rendered (in avirtual reality viewing device or an augmented reality viewing device)or to see real objects in the actual world around the user (in anaugmented reality viewing device).

Visual perception devices such as augmented reality viewing devices,virtual reality viewing devices, prescription and nonprescriptionglasses usually have a nose piece. The nose piece fits over the user'snose and assist in carrying the weight the visual perception device. Anose piece of a visual perception device is usually not interchangeableto fit different users.

SUMMARY OF THE INVENTION

The invention provides a visual perception device including a viewingdevice frame that includes at least a first viewing device framecomponent, at least a first viewing component secured to the viewingdevice frame, an insert frame that includes at least a first correctivecomponent and an attachment system that includes at least a firstmagnetic set having first and second connecting components secured tothe first viewing device frame component and the insert framerespectively, the first and second connecting components of the firstmagnetic set being attracted to one another by a north-south magneticattraction when located in proximity to one another to secure the insertframe to the first viewing device frame component

The invention further provides a method of visually perceiving lightincluding locating first and second connecting components in proximityto one another, the connecting components being attracted to one anotherby a north-south magnetic attraction to secure a corrective component toa frame component and assemble a visual perception device andpositioning the visual perception device over an eye with light beingtransmitted from a viewing component that is secured to the framecomponent, the corrective component being located in a path of the lightto correct a refractive error of a lens of the eye and improve focusingof light on a retina of the eye.

The invention also provides a visual perception device including aviewing device frame, at least a first viewing component secured to theviewing device frame, an insert having at least a first viewing rim andan attachment system that includes at least a first magnetic set thatincludes first and second connecting components secured to the viewingdevice frame and the insert respectively, the connecting components ofthe first set being attracted to one another by a north-south magneticattraction when located in proximity to one another to secure the insertto the viewing device frame with the first viewing component viewablethough the first viewing rim.

The invention further provides a method of visually perceiving lightincluding locating first and second connecting components in proximityto one another, the connecting components being attracted to one anotherby a north-south magnetic attraction to secure an insert to a viewingdevice frame to assemble a visual perception device with a first viewingcomponent that is mounted to the viewing device frame viewable though afirst viewing rim of the insert and positioning the visual perceptiondevice over an eye with light being transmitted from a viewing componentsecured to the frame component and the light passing through firstviewing rim and focusing on a retina of the eye.

The invention also provides a visual perception device including firstand second viewing components, a viewing device frame that includes atleast a viewing device frame bridge connecting the first and secondviewing components to one another, first and second correctivecomponents, an insert frame that includes at least an insert framebridge connecting the first and second corrective components to oneanother to form an insert and an attachment system that includes a nosepiece, the nose piece and the viewing device frame bridge having firstand second inter-engaging locking formations respectively that areconnectable to one another to mount the nose piece to the viewing deviceframe bridge, the nose piece having an upper surface contacting theinsert frame bridge to hold the insert frame bridge in place against theviewing device frame bridge.

The invention further provides a method of visually perceiving lightincluding removably mounting a nose piece to viewing device frame bridgeto secure a corrective component to the frame bridge and assemble avisual perception device and positioning the visual perception deviceover an eye with light being transmitted from a viewing componentsecured to the frame component and the corrective component in a path ofthe light to correct a refractive error of a lens of the eye and improvefocusing of light on the retina of the eye.

The invention also provides a visual perception device including a firstnose piece that may include a respective locking component, a respectivenose pad having a respective nose bridge portion and respective firstand second nose tabs defining a respective inverted channel shape, arespective stem connecting the respective second locking component tothe respective nose bridge portion, a respective first locking formationon the respective locking component, first and second viewingcomponents, a viewing device frame that includes at least a viewingdevice frame bridge connecting the first and second viewing componentsto one another and a second locking formation on the viewing deviceframe bridge, the second locking formation and the respective firstlocking formation being first and second inter-engaging lockingformations respectively that are connectable to one another to removablymount the first nose piece to the viewing device frame bridge.

The invention further provides a method of visually perceiving lightincluding removably mounting a nose pad to a viewing device frame bridgeand positioning the nose pad on a nose of a user, the nose pad having anose bridge portion and first and second nose tabs defining an invertedchannel shape, the nose bridge portion forming part of a viewing deviceframe that includes the viewing device frame bridge connecting first andsecond viewing components.

The invention also provides a visual perception device including abionicle frame, a viewing component mounted to the bionicle frame, ashell piece, a nose piece mounted to the shell piece, the nose piecehaving first and second nose pads and a pliable member, the shell piecebeing connected to the bionicle frame through the pliable member.

The invention further provides a visual perception device including abionicle frame, a viewing component mounted to the bionicle frame, ashell piece, a nose piece mounted to the shell piece, the nose piecehaving first and second nose pads and a barrier component locatedbetween the bionicle frame and the nose piece.

The invention also provides a visual perception device including a datachannel to hold data representing an image, a projector connected to thedata channel to convert the data into light representing the image andtransmit the light representing the image as at least a first componentof the light, wherein at least a second component of the light istransmitted from a surface of a real object simultaneously with thefirst component of the light and a corrective component through which atleast one of the first component and second component of the lighttransmits before being refracted by a lens of an eye and then falling ona retina of the eye, the corrective component correcting a refractiveerror of the lens of the eye to improve focusing of the at least onecomponent of the light on the retina of the eye.

The invention further provides a method of visually perceiving lightincluding converting data representing an image into a first componentof light representing the image, transmitting the at least firstcomponent of the light, the at least a first component of the lighttransmitting through a lens of an eye, wherein at least a secondcomponent of the light is transmitted from a surface of a real objectthrough the lens of the eye simultaneously with the first component ofthe light and placing a corrective component in a path of the light tocorrect a refractive error of the lens of the eye and improve focusingof at least one of the first and second components of the light on theretina of the eye.

The invention also provides a visual perception device including a datachannel to hold data representing an image, a projector connected to thedata channel to convert the data into at least a first component oflight representing the image and transmit the at least a first componentof the light and a corrective component through which the at least firstcomponent of the light transmits before being refracted by a lens of aneye and then falling on a retina of the eye, the corrective componentcorrecting a refractive error of the lens of the eye to improve focusingof the at least first component of the light on the retina of the eye.

The invention further provides a method of visually perceiving lightincluding converting data representing an image into at least a firstcomponent of light representing the image, transmitting at least a firstcomponent of the light through a lens of the eye and placing acorrective component in a path of the at least a first component of thelight to correct a refractive error of the lens of the eye and improvefocusing of the at least first component of the light on the retina ofthe eye.

The invention also provides a visual device including a lens and atleast a first infrared pass filter on the lens, the lens passing moreinfrared light with the first infrared pass filter than without theinfrared pass filter.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is further described by way of examples with reference tothe accompanying drawings, wherein:

FIG. 1 is a perspective view of a visual perception device, according toan embodiment of the invention, including a viewing device, aprescription insert, and an attachment system to secure the prescriptioninsert to the viewing device;

FIG. 2 is a cross-sectional view of the viewing device with theprescription insert in place using the attachment system in FIG. 1 ;

FIG. 3 is a front view of the visual perception device;

FIG. 4 is a side view illustrating optical components of the visualperception device;

FIGS. 5A and 5B are side views illustrating correction of myopia whenviewing a real object using a lens of the prescription insert;

FIGS. 6A and 6B are side views illustrating correction of myopia of arendered image;

FIG. 7 is a side view and a block diagram illustrating image generationand eye tracking components of the visual perception device;

FIG. 8 is a front view of a nonprescription insert that can be usedinstead of the prescription insert of FIG. 1 ;

FIG. 9 is perspective view of a visual perception device having anattachment system that includes a nose piece that is used to attach anonprescription insert to a viewing device;

FIG. 10 is a perspective view of the nose piece and an anchor piece;

FIG. 11 is a rear view of portions of the nose piece and the anchorpiece after they have been attached to one another;

FIG. 12 is a front view illustrating the use of a short nose piece;

FIG. 13 is a front view illustrating the use of a longer nose piece thanin FIG. 12 ;

FIG. 14 is a perspective view in cross-section on A-A in FIG. 3 ; and

FIG. 15 is a perspective view in cross-section on B-B in FIG. 3 .

DETAILED DESCRIPTION OF THE INVENTION

FIG. 1 illustrates a visual perception device 10 that includes a viewingdevice 12, a prescription insert 14, and an attachment system 16 that isused to secure the prescription insert 14 to the viewing device 12.

The viewing device 12 includes a viewing device frame 18, a firstviewing component 20 and second viewing component 22. The first andsecond viewing components 20 and 22 may include lenses, waveguides, andother optical components or assemblies thereof. The first and secondviewing components 20 and 22 are preferably partially or fullytransparent such that a user can see through them to a scene.

The viewing device frame 18 includes a viewing device frame bridge 24, afirst viewing device rim 26, a second viewing device rim 28, and a firsttemple piece 30. The viewing device frame bridge 24 connects the firstand second viewing device rims 26 and 28 to one another. Each viewingdevice rim 26 and 28 defines a respective opening. The first viewingcomponent 20 is mounted within the opening of the first viewing devicerim 26. The second viewing component 22 is mounted within the opening ofthe second viewing device rim 28. The first temple piece 30 is attachedto the second viewing device rim 28 on a side of the second viewingcomponent 22 opposing the viewing device frame bridge 24. The firsttemple piece 30 may extend from viewing device frame 18 toward the userand contact at least a portion of the user's head. In the givenembodiment, the first temple piece 30 extends in a direction that isapproximately at right angles to a plane of the first and second viewingcomponents 20 and 22; although a range of angles may also be possibledepending on a width of a user's head.

A second temple piece (not shown) is attached to the first viewingdevice rim 26 on a side of the first viewing component 20 opposing theviewing device frame bridge 24. The second temple piece extends in adirection that is substantially parallel to the first temple piece 30.

In use, a user wears the viewing device 12 on their head. The first andsecond viewing components 20 and 22 are positioned in front of right andleft eyes, respectively, of the user. The temple pieces 30 may form partof, or may be attached to, a strap or a rigid or semi-rigid band aroundthe back of the head of the user to secure the viewing device frame 18to the head of the user. The user can then view content that istransmitted from the first and second viewing components 20 and 22 totheir eyes. Because the viewing device 12 is secured to their head, theuser can move their head and the viewing device 12 moves with their headso that the first and second viewing components 20 and 22 always remainin front of their eyes.

Although an embodiment is described wherein the first temple piece 30forms part of a strap or band around a head of a user, alternativesystems can be used for attaching a viewing device to a head of a user.For example, an ear piece can be provided that anchors on an ear of auser instead of a strap or band that goes around the head of the user.Furthermore, although first and second viewing components 20 and 22 aredescribed, aspects of the invention may find application in designswhere only a single viewing component is provided.

The prescription insert 14 includes an insert frame 32, a firstcorrective component in the form of a first lens 34, and a secondcorrective component in the form of a second lens 36.

The insert frame 32 has an insert frame bridge 38 and first and secondinsert frame rims 40 and 42. The insert frame rims 40 and 42 areconnected to one another via the insert frame bridge 38. The insertframe rims 40 and 42 define respective openings. The first and secondlenses 34 and 36 are inserted into the respective openings of the firstand second insert frame rims 40 and 42. The first and second lenses 34and 36 are secured to the first and second insert frame rims 40 and 42using a conventional mechanism such as an interference fit or the like.

The viewing device 12 and the prescription insert 14 are separateassemblies that can be obtained separately by a user. The first andsecond lenses 34 and 36 may be prescription lenses with corrections thatare prescribed by an optician and are unique to the particular user. Byproviding the viewing device 12 and the prescription insert 14separately to the user, there is no requirement to build correctiveoptics unique to the user into the viewing device 12. The user may, astheir eyesight changes over time, replace the first and second lenses 34and 36 with new lenses that are based on new corrective recommendationsof new prescriptions. In another scenario, multiple users, each withdifferent eyesight, may share a single viewing device while having aunique prescription insert customized to the specific eyesight of eachuser. In the latter scenario, the prescription inserts of the differentusers may be removably attached to the viewing device 12 usingcompatibly similar attachment systems as described herein.

The attachment system 16 includes first and second magnetic sets 50 and52. The magnetic sets 50 and 52, together with other features, are usedto removably secure the prescription insert 14 to the viewing device 12.

The first magnetic set 50 includes a first connector component in theform of a ferromagnetic component 54 and a second connector component inthe form of a permanent magnet 56. The permanent magnet 56 is secured tothe viewing device frame 18. A region where the permanent magnet 56 issecured to the viewing device frame 18 is referred to herein as a “firstviewing device frame component 58”. The permanent magnet 56 is insertedinto an opening in the first viewing device frame component 58. Thepermanent magnet 56 may be secured to the first viewing device framecomponent 58 using an interference fit, an adhesive or the like. Thepermanent magnet may alternatively be installed from an opposing sideand be secured with an adhesive.

The permanent magnet 56 is located in a stationary position relative tothe viewing device frame 18. Its location and flux density can beaccounted for when calculating potential electromagnetic interferencebetween the permanent magnet 56 and electronics that reside within theviewing device frame 18. Thus, while it is possible to have a permanentmagnet placed on the prescription insert and a ferromagnetic componentplaced on the frame, such an arrangement may require recalibration ofon-board electronic components when a prescription insert is attachedand removed to account for changes in the nearby magnetic field as afunction of presence or absence of permanent magnets on the prescriptioninsert.

The ferromagnetic component 54 is inserted into an opening within theinsert frame bridge 38. The ferromagnetic component 54 may be secured tothe insert frame bridge 38 using an interference fit, an adhesive or thelike. The ferromagnetic component 54 is not a permanent magnet and isthus unlikely to attract magnetic particles when it is separated fromthe viewing device 12. A user that fits the first and second lenses 34and 36 may thus do so without magnetic dust accumulating on theferromagnetic component 54.

The second magnetic set 52 incudes a first connector component in theform of a ferromagnetic component 60 and second connector in the form ofa permanent magnet 62. The permanent magnet 62 is secured to a secondviewing device frame component 64 forming part of the viewing deviceframe 18. The ferromagnetic component 60 is secured to the insert framebridge 38.

The ferromagnetic components 54 and 60 are located on opposite sides ofa center line that divides the insert frame bridge 38 in half. Centerpoints of the ferromagnetic components 54 and 60 are spaced from oneanother by the same distance as center points of the permanent magnets56 and 62. The positioning of the ferromagnetic components 54 and 60relative to the first and second lenses 34 and 36 is the same as therelative positioning of the permanent magnets 56 and 62 to the first andsecond viewing components 20 and 22 such that when the prescriptioninsert is attached to viewing device, the first and second viewingcomponents 20 and 22 are substantially concentric with the first andsecond lenses 34 and 36 and the permanent magnets 56 and 62 aresubstantially concentric with the ferromagnetic components 54 and 60.For example, a distance from a center point of the ferromagneticcomponent 54 to a center point of the first lens 34 is the same as adistance from a center point of the permanent magnet 56 to a centerpoint of the first viewing component 20.

FIG. 2 further illustrates a first pin 78 and first guide opening 80.The first pin 78 is secured to and extends from the insert frame bridge38. The first guide opening 80 is located within the viewing deviceframe bridge 24. The first pin 78 has a tip 82 and a body 84. The tip 82has a slightly smaller cross section than the body 84.

In use, a user roughly aligns the prescription insert 14 with theviewing device 12 so that the first lens 34 is located over the firstviewing component 20 and the second lens 36 is located over the secondviewing component 22. The user then moves the prescription insert 14closer to the viewing device 12. The first pin 78 is inserted into thefirst guide opening 80 when the insert frame bridge 38 approaches theviewing device frame bridge 24 and before the ferromagnetic component 54contacts the permanent magnet 56. The smaller cross section of the tip82 allows for slight misalignments between a center line of the firstpin 78 and a center line of the first guide opening 80. As the first pin78 is further inserted into the first guide opening 80, the body 84enters the first guide opening 80. The body 84 is only slightly smallerthan the first guide opening 80, which causes the center line of thefirst pin 78 to come into alignment with a center line of the firstguide opening 80.

As the prescription insert 14 approaches the viewing device 12, theferromagnetic components 54 and 60 enter into the magnetic fields of thepermanent magnets 56 and 62, respectively. The magnetic fields of thepermanent magnets 56 and 62 cause the ferromagnetic components 54 and 60to become magnetic. The ferromagnetic components 54 and 60 are thenattracted to the permanent magnets 56 and 62, respectively, bynorth-south magnetic attraction. As the user places the prescriptioninsert 14 against the viewing device 12, the magnetic field createdthrough the permanent magnet 56 and the ferromagnetic component 54assist in further aligning the ferromagnetic component 54 with thepermanent magnet 56. Similarly, the ferromagnetic component 60 alignswith the permanent magnet 62. The magnetic attraction between theferromagnetic component 54 and the permanent magnet 56 causes theferromagnetic component 54 to come into contact with the permanentmagnet 56, at which time the first pin 78 is fully inserted into thefirst guide opening 80. The user then releases the prescription insert14. The prescription insert 14 is secured to the viewing device 12 byway of the permanent magnets 56 and 62 and the ferromagnetic components54 and 60. The first lens 34 is then aligned with the first viewingcomponent 20 and the second lens 36 is aligned with second viewingcomponent 22.

Interaction between the first pin 78 and an internal surface of thefirst guide opening 80 prevents movement in a direction 86 of the insertframe bridge 38 relative to the viewing device frame bridge 24. Theinsert frame bridge 38 is thus locked into place against movement in thedirection 86 relative to the viewing device frame bridge 24. Should theviewing device 12 be bumped or be dropped, and relative forces arecreated between the insert frame bridge 38 and the viewing device framebridge 24 in a direction parallel to the direction 86, the interactionbetween the first pin 78 and the first guide opening 80 will preventmovement of the insert frame bridge 38 relative to the viewing deviceframe bridge 24 in a direction in a same plane as the direction 86. Forexample, the interaction between first pin 78 and first guide opening 80may substantially prevent relative motion between the prescriptioninsert and the viewing device in any direction orthogonal to an axis offirst pin 78.

Should the user wish to remove the prescription insert 14, the userholds on to a portion of the insert frame 32 and then moves theprescription insert 14 away from the viewing device 12. Such movementcauses the ferromagnetic components 54 and 60 to separate from thepermanent magnets 56 and 62 until their magnetic attraction is broken.

The advantages of having permanent magnets on the viewing device 12 andferromagnetic components on the prescription insert 14 have beendetailed above. Aspects of the invention may not be limited to such anarrangement. For example, it may be possible to have permanent magnetson the prescription insert 14 and ferromagnetic components on theviewing device 12. It may also be possible to only have permanentmagnets and no ferromagnetic components. In each case there will benorth-south magnetic attraction between first and second connectorcomponents on the prescription insert 14 and the viewing device 12 tosecure the prescription insert 14 to the viewing device 12.

The invention has been described by way of example with first and secondmagnetic sets 50 and 52. More than one magnetic set allows for forces tobe distributed across the prescription insert 14 and also assists inangular alignment of the prescription insert 14 relative to the viewingdevice 12. Aspects of the invention may find application in deviceshaving more than two magnetic sets or only a single magnetic set.Additionally, while a symmetric system is shown, one of skill in the artwill appreciate that the magnetic sets 50 and 52 may be arranged in anyadvantageous configuration to provide sufficient attraction forcesbetween the prescription insert 14 and the viewing device 12. Moreover,while the magnetic sets 50 and 52 are shown placed medial to the viewingcomponents 20 and 22 and lenses 34 and 36, it is possible to place themagnetic sets 50 and 52, or additional magnetic sets, above, below, orlateral to the viewing components 20 and 22 and lenses 34 and 36 asfound to be advantageous for reduced electrical interference, morepleasing form factor, or other reasons.

The viewing device 12 further includes a head pad 70 secured to theviewing device frame bridge 24. The head pad 70 rests against a foreheadof a user wearing the viewing device 12. The head pad 70 providescomfort to the user because it is generally made of a softer materialthan the viewing device frame 18 and also assists in insulating the userfrom heat generated by onboard electrical components. The head pad 70also assists in securing the viewing device 12 to the head of the user,especially if the first temple piece 30 forms part of a strapsurrounding the head of the user. The head pad 70 extends outwardly fromthe viewing device frame 18 towards the head of the user wearing theviewing device 12 which advantageously provides a shield for light thatmay otherwise enter from above between the viewing device frame bridge24 and the forehead of the user wearing the viewing device 12.

The prescription insert 14 further includes first and second eye cups 72and 74. The first eye cup 72 is secured to the first insert frame rim 40and extends from the first insert frame rim 40 towards the head of theuser wearing the viewing device 12. The first eye cup 72 prevents lightthat may enter from approximately a 12 o'clock position to approximatelya 2 o'clock position between the first insert frame rim 40 and the headof the user wearing the viewing device 12. A shape of the first eye cup72 cooperates with a shape of the head pad 70 to minimize orsubstantially eliminate light entering from above.

The second eye cup 74 is secured to and extends from the second insertframe rim 42. The second eye cup 74 prevents light from entering fromapproximately a 10 o'clock position to approximately a 12 o'clockposition between the second insert frame rim 42 and a head of a userwearing the viewing device 12. The second eye cup 74 cooperates with thehead pad 70 to minimize or substantially eliminate light from enteringfrom above.

FIG. 2 shows the first magnetic set 50 after the ferromagnetic component54 is magnetically attached to the permanent magnet 56 of the firstmagnetic set 50. The magnetic attraction between the ferromagneticcomponent 54 and the permanent magnet 56 resists removal of the insertframe bridge 38 in a direction 76 away from the viewing device framebridge 24. The magnetic attraction between the ferromagnetic component54 and the permanent magnet 56 of the first magnetic set 50 shown inFIGS. 1 and 2 and the magnetic attraction between the ferromagneticcomponent 60 and the permanent magnet 62 of the second magnetic set 52shown in FIG. 1 is sufficient to hold the insert frame bridge 38 againstthe viewing device frame bridge 24 provided that the viewing device 12is not excessively bumped or is not dropped onto the ground, forexample. The magnetic attraction is still sufficiently weak to allow fora user to remove the prescription insert 14 from the viewing device 12.The magnets are typically Grade N52 magnets that have a diameter of 4 mmand a height of 2 mm and impart approximately 0.94 lbs. force each.

The attachment system 16 thus secures the insert frame bridge 38 to theviewing device frame bridge 24 and prevents movement of the insert framebridge 38 relative to the viewing device frame bridge 24 in thedirections 76 and 86. The first pin 78 and the first guide opening 80have center lines that extend in a direction permitting a user to removethe insert frame bridge 38 from the viewing device frame bridge 24. Whenthe user thus breaks the magnetic attraction between the ferromagneticcomponent 54 and the permanent magnet 56, the first pin 78 withdrawsfrom the first guide opening 80 as the insert frame bridge 38 is removedfrom the viewing device frame bridge 24.

As shown in FIG. 1 , a second guide opening 88 is provided within theviewing device frame bridge 24. The first and second guide openings 80and 88 are located on opposite sides of a vertical center line of theviewing device frame bridge 24. The first pin 78 is aligned with thefirst guide opening 80. The prescription insert 14 further includes asecond pin 90. The first and second pins 78 and 90 are located onopposite sides of vertical center line of the insert frame bridge 38. Adistance between center points of the first and second guide openings 80and 88 is the same as a distance between center lines of the first andsecond pins 78 and 90. The first and second pins 78 and 90 engagesimultaneously with the first and second guide openings 80 and 88,respectively, when the prescription insert 14 is moved towards theviewing device 12.

The inclusion of two pins 78 and 90 assists in distributing forcesacross the prescription insert 14 and prevents angular misalignmentbetween the prescription insert 14 and the viewing device 12. It willhowever be understood that a single pin and a single guide opening mayprovide an interlocking arrangement and that more than two sucharrangements may further distribute stresses across the prescriptioninsert 14. It will also be understood that the number of pins need notmatch the number of magnetic sets. For example, there may be more orfewer pins than magnetic sets.

The viewing device 12 further includes a nose piece 92 that is securedto the viewing device frame bridge 24. The nose piece 92 is connected tothe viewing device frame bridge 24 before or after the prescriptioninsert 14 is attached to the viewing device 12. A lower surface of theinsert frame bridge 38 and an upper surface of the nose piece 92 arecomplementary in shape, which allows for the insert frame bridge 38 tobe positioned over the nose piece 92 during installation. A lowersurface of the nose piece 92 is shaped to fit over a nose of the userwearing the visual perception device 10. The material of the nose piece92 may be selected to have some elasticity or compliance such that avariety of nose shapes may be accommodated while maintaining a desiredcomfort level. The nose piece 92 has first and second nose tabs 94 and96 that contact opposing sides of the nose of the user wearing thevisual perception device 10.

As shown in FIG. 3 , the second insert frame rim 42 and the second lens36 have complementary shapes that allow for the second lens 36 to beinserted into the second insert frame rim 42 in a first orientation witha first side of the second lens 36 facing towards the second viewingcomponent 22 (see FIG. 1 ) and disallow the second lens 36 from beinginserted into the second insert frame rim 42 in a second orientationwherein the first side of the second lens 36 faces away from the secondviewing component 22. The second lens 36 can thus not be rotated in adirection 104 about a vertical center line 106 and still fit. Inparticular, the shape of the second insert frame rim 42 includes firstand second curves 100 and 102 that have different radiuses, R1 and R2,that match respective radiuses of the second lens 36 in the firstorientation and prevent insertion of the second lens 36 into the secondinsert frame rim 42 when the second lens 36 is rotated in a directionabout a vertical axis into the second orientation. The second insertframe 42 has a flat section 108. A line 110 that extends at right anglesfrom a center point of the flat section is offset by a distance 112 froma center point 114 of the second lens 36. The positioning of the flatsection 108 relative to the center point 114 further prevents insertionof the second lens 36 into the second insert frame rim 42 when in thesecond orientation. One of skill in the art will appreciate that variousasymmetries and/or geometries may be built into lenses and insert framerims to prevent improper orientation of the lenses, either upside downor switched between the left and right.

Proper alignment of spherical and cylindrical corrective features of thesecond lens 36 is ensured by permitting the second lens 36 to beinserted into the second insert frame rim 42 in the first orientation,but not in the second orientation. The first lens 34 and the firstinsert frame rim 40 have complementary shapes that allow for the firstlens 34 to be inserted into the first insert frame rim 40 when the firstlens 34 is in a first orientation, but disallow insertion of the firstlens 34 into the first insert frame rim 40 when the first lens 34 is ina second orientation with a surface thereof that should face towards thefirst viewing component 20 (see FIG. 1 ) facing away from the firstviewing component 20.

The complementary features of the first and second lenses 34 and 36 withrespect to the first and second insert frame rims 40 and 42 thus preventreversed insertion of the first and second lenses 34 and 36. Thefeatures are particularly useful because the first and second lenses 34and 36 are premanufactured to prescribed proportions and cannot easilybe reshaped after they have been inserted into the first and secondinsert frame rims 40 and 42. It should however be understood thataspects of the invention may find application where correctivecomponents other than lenses with fixed corrective dimensions are used.For example, aspects of the invention may find application usingcorrective components such as adaptive lenses or corrective componentsusing liquid crystal display technology. Such corrective components mayor may not have the ability to adjust corrective features after theyhave been installed. Complementary shapes between such correctivecomponents and the insert frame rims into which they are installed mayor may not require complementary shapes that prevent reversedinstallation, depending on whether such corrective components can adjustfor spherical and cylindrical alignment of corrective features.

The viewing device 12 includes a plurality of infrared emitters 118 andtwo eye tracking cameras 120. The infrared emitters 118 are positionedto emit infrared light through the first and second lenses 34 and 36.The eye tracking cameras 120 are positioned to receive infrared lightthrough the first and second lenses 34 and 36. The ferromagneticcomponents 54 and 60 and the first and second pins 78 and 90 are locatedbehind the insert frame bridge 38 and are not visible in the view ofFIG. 3 . The insert frame 32 is shaped to hide the first and second pins78 and 90 and the ferromagnetic components 54 and 60 while allowinglight to transmit from the infrared emitters 118 through the first andsecond insert frame rims 40 and 42 and for infrared light to transmitthrough the first and second insert frame rims 40 and 42 to the eyetracking cameras 120.

FIG. 4 illustrates the positioning of one of the infrared emitters 118,one of the eye tracking cameras 120, the first lens 34, the firstviewing component 20 and an eye 122 relative to one another. The firstlens 34 has a first side 124 and second side 126 opposing the first side124. The infrared emitter 118 and the eye tracking camera 120 arelocated on the first side 124 of the first lens 34. The eye 122 islocated on the second side 126 of the first lens 34.

The first lens 34 is made of acrylic glass, thermoset, or thermoplasticmaterial or another material that reflects infrared light or a largefraction of infrared light. The first and second infrared pass filters128 and 130 are made of a material that is conducive to passing infraredlight.

The first viewing component 20 has first and second opposing surfaces132 and 134. The first and second opposing surfaces 132 and 134 areplanar surfaces that are located in parallel planes relative to oneanother such that light entering eyes of a user through the viewingcomponent 20 has little to no distortion. The first side 124 of thefirst lens 34 is a planar surface. Because the first side 124 of thefirst lens 34 is a planar surface and the second surface 134 of thefirst viewing component 20 is also a planar surface, the first lens 34can be positioned as close as possible to the first viewing component20.

The second side 126 of the first lens 34 has a concave shape that can beadjusted to accommodate for various myopic vision correctionprescriptions. The concave shape of the second side 126 allows for thefirst lens 34 to be located between the eye 122 and the first viewingcomponent 20 while still allowing sufficient space between the eye 122and the first lens 34 without danger that the first lens 34 may comeinto contact with the eye 122 or eyelashes during blinking.

The combination of the planar first side 124 and the concave second side126 of the first lens 34 thus allows for the first lens 34 to be addedbetween the first viewing component 20 and the eye 122. Another lensshape, for example where the first side 124 is convex may result in alens shape that may be too close to the eye 122.

In use, the infrared emitter 118 emits electromagnetic waves in the formof infrared light 138. The first infrared pass filter 128 absorbs theinfrared light 138. The infrared light 138 transmits through the firstinfrared pass filter 128 into the first lens 34. The first lens 34absorbs more of the infrared light 138 due to the first infrared passfilter 128 than without it.

The infrared light 138 then transmits from the first lens 34 through thesecond infrared pass filter 130, and then through an air space betweenthe second infrared pass filter 130 and the eye 122. The infrared light138 then reflects off a surface of the eye 122 as infrared light 140.

The infrared light 140 then travels through the airspace between the eye122 and the second infrared pass filter 130. The second infrared passfilter 130 absorbs the infrared light 140. The infrared light 140travels through the second infrared pass filter 130 into the first lens34. The first lens 34 absorbs more of the infrared light 140 due to thesecond infrared pass filter 130 than without it.

The infrared light 140 then travels out of the first lens 34 and throughthe first infrared pass filter 128 to the eye tracking camera 120. Theeye tracking camera 120 then detects the infrared light 140. The eyetracking camera 120 also receives infrared light, as represented byinfrared light rays 142 and 144, from other locations on the eye 122.The infrared light that is received by the eye tracking camera 120originates from the infrared emitter 118 shown in FIG. 4 and the otherinfrared emitters 118 that are visible through the first insert framerim 40 in FIG. 3 . Eye movement is tracked through changes in infraredlight source reflecting off eye. The eye tracking camera 120 captures animage of the eye 122 from the infrared light that is reflected. Theimage of the eye 122 and the movement of infrared light reflections offof the eye as captured by the eye tracking camera 120 may change as theeye 122 moves. The changing infrared light reflections correlate tomovements and positions of the eye 122 such that eye position can beinferred from reflection patterns captured by eye tracking camera 120.

FIGS. 5A and 8 illustrate how the first lens 34 corrects for myopia whenviewing a real object. In FIG. 5A, the first lens 34 is not installed. Afirst component of light 146 travels from a real object (not shown)through the first viewing component 20 to the eye 122. A lens 148 of theeye 122 refracts the first component of light 146 so as to focus thefirst component of light 146 at a focal point 150. In an eye that hasperfect vision, the focal point is precisely on the retina in such aneye. In myopic vision, such as for the eye 122, the focal point 150 islocated between a retina 152 and the lens 148 of the eye 122. The lightbegins to fan out as it moves from the focal point 150 toward the retina152 such that when the first component of light 146 reaches the retina152, the retina 152 detects an out-of-focus blurred image.

FIG. 5B illustrates the effect of the first lens 34 to correct for themyopic vision in FIG. 5A. The first lens 34 refracts the first componentof light 146 before the first component of light 146 reaches the lens148 of the eye 122. When the lens 148 of the eye 122 refracts the light,the lens 148 focuses the light at a focal point 154 on the retina 152.The first lens 34 thus corrects for myopic vision such that the firstcomponent of light 146 is in focus to the viewer.

FIG. 6A illustrates further components of the viewing device 12,including a data channel 158 and a projector 160. The projector 160 issecured to the viewing device frame 18 in FIG. 1 .

In use, the data channel 158 carries data representing an image. Theprojector 160 is connected to the data channel 158 and converts the datapresenting the image into a second component of light 162. The projector160 is positioned to direct the second component of light 162 into thefirst viewing component 20. The second component of light 162 enters thefirst viewing component 20 and the first viewing component 20 then actsas a wave guide through which the second component of light 162 travelswhile being reflected within the first viewing component 20. The secondcomponent of light 162 exits the first viewing component 20 through apupil 164 towards the lens 148 of the eye 122. The lens 148 refracts thesecond component of light 162 and focuses the second component of light162 at a focal point 166. Because of the myopic conditions of the eye122, the focal point 166 is spaced from the retina 152 and locatedbetween the retina 152 and the lens 148 of the eye 122.

The user perceives a rendered image at a distance behind the firstviewing component 20 due to the shaped wavefront of the image beingtransmitted from the pupil 164 toward the eye 122. The shape of thewavefront determines how far away the user will perceive the virtualimage to be. As a user focuses on the virtual image, the naturalaccommodation/vergence response occurs to bring the virtual image intofocus at the perceived depth. However, because of the myopic conditionsof the eye 122, if the distance of the virtual image is outside of arange that the lens 148 of the eye 122 can correct, an out-of-focusblurred virtual image will be seen by the user.

As shown in FIG. 6B, the second lens 36 refracts the second component oflight 162 before the second component of light 162 reaches the lens 148of the eye 122. When the lens 148 of the eye 122 again refracts thelight, the light focuses at a focal point 166 on the retina 152.

The first and second components of light 146 and 162 fall on the retina152 simultaneously. As a result, the user sees the real object and theimage simultaneously. The first lens 34 brings both the real object andthe image into focus at the same time, assuming the light isoriginating, or appears to be originating, from the same depth from theeyes.

FIG. 7 illustrates further components of the viewing device 12,including an image generator 170, an image source 172, an eye trackingcalibration module 174 and eye tracking calibration data 176.

The image generator 170 is connected to the eye tracking camera 120 andto the image source 172. The image source may, for example, be a staticimage, a video stream or image data that is being captured in real time.The image generator 170 utilizes the image from the image source 172 anddata from the eye tracking camera 120 to generate image data. The imagegenerator 170 provides the image data through the data channel 158 tothe projector 160.

The eye tracking camera 120 tracks movement of the eye 122 for purposesof determining an orientation of the eye 122. The image generator 170modifies the image from the image source 172 based on data from the eyetracking camera 120. The first viewing component 20 may for example havea plurality of pupils and the image generator 170 may provide more lightto one pupil than to another pupil of the first viewing component 20depending the orientation of the eye 122. The eye tracking cameras 120of both eyes 122 can jointly determine an orientation of the eyes 122relative to one another. Such data may facilitate a reduction inaccommodation-and-vergence mismatches by rendering the image at aparticular field of depth.

The eye tracking calibration module 174 is used to generate the eyetracking calibration data 176 before the image generator 170 is used togenerate an image for a user. The eye tracking calibration module 174utilizes data from the eye tracking camera 120 to generate the eyetracking calibration data 176. The eye tracking camera 120 receivesimage data of the eye 122 through the first lens 34. The image data thatis received by the eye tracking camera 120 is different when the firstlens 34 is included than when the first lens 34 is absent. The eyetracking calibration module 174 is configured to generate the eyetracking calibration data 176 without the inclusion of the first lens 34and to compensate for the inclusion for the first lens 34 when it ispresent. The image generator 170 utilizes the eye tracking calibrationdata 176 to generate the image data for purposes of providing to thedata channel 158. The image generator 170 thus generates substantiallythe same image data irrespective of whether the eye tracking calibrationdata 176 is generated when the first lens 34 is absent or included.

The first lens 34 is a plano-concave lens. As described above, aplano-concave lens is suitable for correcting a refractive error duo tomyopia and can easily fit between the first viewing component 20 and theeye 122 without much danger that the first lens 34 will contact the eye122. Aspects of the invention may find application when another lens isused, for example a biconvex, plano-convex, convex-concave, meniscus, ora biconcave lens. In addition to myopia, a lens that corrects for arefractive error due to astigmatism may fit easily between the firstviewing component 20 and the eye 122. Aspects of the invention may alsofind application for corrections of other refractive errors, such ashyperopia or presbyopia without departing from such aspects of theinvention.

FIG. 8 illustrates a nonprescription insert 180, according to anotherembodiment of the invention. The nonprescription insert 180 includes aninsert frame 182, ferromagnetic components 188 and 190, first and secondpins 192 and 194 and first and second eye cups 196 and 198. Thenonprescription insert 180 is similar to the prescription insert 14 ofFIG. 1 with respect to these features.

The nonprescription insert 180 does not have any lenses that areinstalled. As such, there is no danger that any lenses may beinadvertently reversed during installation. The insert frame 182 hasfirst and second insert frame rims 200 and 202 that do not have thefeatures of the first and second insert frame rims 40 and 42 in FIG. 1that prevent reversed insertion of the first and second lenses 34 and36.

The prescription insert 14 and the nonprescription insert 180 are fullyinterchangeable. A user can remove the prescription insert 14 from theviewing device 12 by overcoming the magnetic connection force and canthen install the nonprescription insert 180 in place of the prescriptioninsert 14.

FIG. 9 illustrates a visual perception device 210, according to anotherembodiment of the invention, that includes the viewing device 12 of FIG.1 , a nonprescription insert 214, and a nose piece 216 that is used tosecure the nonprescription insert 214 to the viewing device 212. Thenonprescription insert 214 is shown by way of example. It should howeverbe understood that a prescription insert may instead be illustrated.

The nonprescription insert 214 includes an insert frame 218. The insertframe 218 includes an insert frame bridge 226 and first and secondinsert frame rims 228 and 230, respectively. The nonprescription insert214 is similar to the nonprescription insert 180 in FIG. 8 with respectto the insert frame 218 in its construction and functioning.

The nonprescription insert 214 further includes a tab 232 extending fromthe insert frame bridge 226. The tab 232 has a lower surface 234 that iscurved. A through opening 236 is formed through the tab 232. The throughopening 236 is formed through only a portion of the tab 232, thusleaving a substantial portion of the lower surface 234 of tab 232 inplace.

The nose piece 216 includes a nose pad 240 and a locking component 242.

The nose pad 240 includes a nose bridge 244 and first and second nosetabs 246 and 248. The nose bridge 244 extends into the first and secondnose tabs 246 and 248 to define an inverted channel shape.

The locking component 242 is secured to the nose bridge 244 and extendsfrom an upper surface 250 of the nose bridge 244. The locking component242 defines a first locking formation 252. The nose piece 216 furtherhas elastic pads 254 on the locking component 242.

FIG. 10 shows the nose piece 216 and an anchor piece 256 in more detail.The anchor piece 256 has a backing plate 258, a second locking formation260, and a stopper portion 262. The second locking formation 260 and thestopper portion 262 are integrally formed with the backing plate 258.The backing plate 258 further has a retaining opening 264.

In FIG. 9 , the anchor piece 256 fits within a complementary recess ofthe viewing device frame bridge 24. A fastener 280 is inserted throughthe retaining opening 264. The fastener 280 is then screwed into theviewing device frame bridge 24, which secures the anchor piece 256 tothe viewing device frame bridge 24. The anchor piece 256 thus forms partof the viewing device 12 and is mounted to the viewing device framebridge 24 before the nonprescription insert 214 and the nose piece 216are mounted to the viewing device 12.

The viewing device frame bridge 24 has a lower surface 288 defining athrough opening 290. The through opening 290 takes up only a portion ofthe real estate of the lower surface 288.

In use, a user locates the nonprescription insert 214 against theviewing device 12 with the first and second insert frame rims 228 and230 positioned over the first and second viewing components 20 and 22,respectively. An upper surface of the insert frame bridge 226 and thelower surface 288 of the viewing device frame bridge 24 are locatedagainst each other. The through opening 236 in the insert frame bridge226 is aligned with the through opening 290 in the viewing device framebridge 24. The user then inserts the locking component 242 of the nosepiece 216 through the through openings 236 and 290.

Referring again to FIG. 10 , the first locking formation 252 includesfirst and second lever arms 294 and 296. Each lever arm 294 or 296 has arespective angular surface 298 and a respective clip formation 300. Theangular surfaces 298 contact inner surfaces of the second lockingformation 260. Further insertion of the first and second lever arms 294and 296 into the second locking formation 260 causes the first andsecond lever arms 294 and 296 to bend towards one another. When thefirst and second lever arms 294 and 296 are further inserted into thesecond locking formation 260, the elastic pads 254 come into contactwith the stopper portion 262. The elastic pads 254 then compress toallow further insertion of the first and second lever arms 294 and 296into the second locking formation 260.

As shown in FIG. 11 , when the clip formations 300 exit the secondlocking formation 260, the first and second lever arms 294 and 296expand outwardly due to their elastic properties. The clip formations300 then reside over the second locking formation 260. The clipformations 300 resist removal of the locking component 242 out of thesecond locking formation 260.

The elastic pads 254 create a force F on a force transfer member 302 ofthe locking component 242. The force F keeps the clip formations 300against the second locking formation 260 to prevent rattling of the nosepiece 216.

Referring to FIG. 9 , the upper surface 250 of the nose pad 240 islocated against the lower surface 234 of the tab 232. With the nosepiece 216 firmly secured to the viewing device 12, the nose pad 240 ofthe nose piece 216 holds the nonprescription insert 214 in position withthe tab 232 sandwiched between the upper surface 250 of the nose pad 240and the lower surface 288 of the viewing device frame bridge 24. Asimilar arrangement can be used for a prescription insert of the kinddescribed above.

FIG. 9 also illustrates the permanent magnet 56. The permanent magnet 56forms part of a first magnetic set that includes the permanent magnet 56and a ferromagnetic component 304. The embodiment of FIG. 9 may includea second magnetic set that includes the permanent magnet 62 of FIG. 1and a ferromagnetic component 306. The nonprescription insert may alsohave first and second pins 308 and 310 that engage with the first andsecond guide openings 80 and 88. The magnetic sets together with thefirst and second pins 308 and 310, the first and second guide openings80 and 88 and the nose piece 216 form an attachment system that securesthe nonprescription insert 214 to the viewing device 12.

Referring again to FIG. 11 , each clip formation 300 has an inclinedsurface 316. The inclined surface 316 is sufficient to retain the clipformation 300 in position against the second locking formation 260. Aslight pull on the nose piece 216 will not cause the clip formation 300to move. The clip formation 300 thus resists disengagement of the firstlocking formation 252 from the second locking formation 260.

A larger force exerted by a user on the nose piece 216 causes theinclined surface 316 to slide on the second locking formation 260. Suchsliding movement of the inclined surfaces depresses the clip formations300 towards one another and bends the first and second lever arms 294and 296. The user can then remove the first locking formation 252 fromthe second locking formation 260.

FIGS. 12 and 13 show two nose pieces, namely the nose piece 216 of FIG.9 and a nose piece 320. The nose pieces 216 and 320 have similarelements and like reference numerals indicate like or similarcomponents. Each nose piece 216 and 320 has a respective stem 322connecting the nose pad 240 to the locking component 242 thereof. Thefirst and second viewing components 20 and 22 have calibration targetsthat are usually in the center of the respective viewing component. Whenthe nose pieces 216 and 320 are installed, a vertical distance d isdefined between the calibration point of the first viewing component 20and a lower surface of the nose pad 240 of the respective nose piece 216or 320. The vertical distance d is smaller when the nose piece 216 isinstalled than when the nose piece 320 is installed. Facial features ofa user are indicated in dotted lines, including their eyes 122 and theirnose 324. The nose pieces 216 or 320 are selected so that the verticaldistance d matches a vertical distance between a center point of arespective user's eyes 122 and the bridge of their nose where the nosepad 240 rests.

A plurality of nose pieces may be provided for the visual perceptiondevice 10. For example, four nose pieces may each have a stem that has adifferent length. The different nose pieces accommodate different facialfeature shapes of different users. The calibration locations on thefirst and second viewing components 20 and 22 are aligned with centerpoint of the eyes 122 of the respective users irrespective of theirfacial features, thus resulting in more accurate calibration. The nosepieces accommodate a range of facial features, shapes and sizes whilemaintaining optimal eye piece positioning for each user so that visualcontent can be perceived by the user.

FIG. 14 illustrates further components of the viewing device 12,including a shell comprised of a front housing 330 and a back housing332, a bionicle frame 334, a fastener 336, a guide pin 338, and apliable member 340.

The bionicle frame 334 is made out of metal. The first and secondviewing components 20 and 22 are secured to the bionicle frame 334. Thefirst and second viewing components 20 and 22 together with the bionicleframe 334 and other components such as electronic sensors and the likemake up a subassembly separate from the other components shown in FIG.14 . The components secured to the bionicle frame 334 are sensitive tosudden impact stresses that may cause damage to these components or movethem out of position. The bionicle frame 334 defines a fastener opening342 and a guide pin opening 344.

The anchor piece 256 is mounted directly to the front housing 330. Thefront housing 330 has a fastener opening 346 and a guide pin opening348.

The back housing 332 has a threaded fastener opening 350 and a guide pinopening 352.

The pliable member 340 is a springable member that is made of anelastomeric material. The pliable member 340 has a guide pin opening 352and a fastener opening 354.

The guide pin 338 is inserted through the guide pin openings 344 and352. An interference fit is created between the guide pin opening 344and the guide pin 338. The pliable member 340 is positioned adjacent thebionicle frame 334 with the guide pin opening 352 aligned with the guidepin opening 344 and with the fastener opening 354 aligned with thefastener opening 342.

A rear end of the guide pin 338 is inserted into the guide pin opening352 of the back housing 332. A front end of the guide pin 338 isinserted into the guide pin opening 348 in the front housing 330. Thefront housing 330 and back housing 332 are brought together in thismanner and contact each other along their perimeters. The bionicle frame334 is held within the shell defined by the front housing 330 and theback housing 332. The pliable member 340 is located between the fronthousing 330 and the bionicle frame 334. Opposing sides of the pliablemember 340 make contact with the front housing 330 and with the bionicleframe 334.

The fastener 336 has a threaded end 356 that is inserted through thefastener openings 346, 354 and 342. The threaded end 356 is then screwedinto the threaded fastener opening 350. The fastener 336 has a shank 358located within the fastener opening 342. A relatively large tolerance isprovided between the fastener opening 342 and the shank 358. Thefastener 336 has a head 360 that is larger than the fastener opening 346so as to rest on a surface of the front housing 330. The threaded end356 and the head 360 at opposing ends of the fastener 336 secure thefastener 336 to the front housing 330 and the back housing 332, and thussecures the front housing 330 and the back housing 332 to one anotherwith the bionicle frame 334 and the pliable member 340 between the fronthousing 330 and the back housing 332.

As mentioned before, the nose piece is secured to the anchor piece 256.When the user moves their head, the user transfers forces from theirnose through the nose piece to the anchor piece 256. These forces arecreated due to acceleration and jerk. The anchor piece 256 transfers theforces to the front housing 330. The front housing 330 transfers theforces to the pliable member 340. The pliable member 340 compresses orexpands so that the forces are not transferred from the front housing330 to the bionicle frame 334, or to reduce the forces that aretransferred. Because of the relatively large tolerance between thefastener opening 342 and the fastener 336, the bionicle frame 334 ispermitted to move relative to the fastener 336. The bionicle frame 334is secured to the guide pin 338 through an interference fit, whichcauses the guide pin 338 to move with the bionicle frame 334 relative tothe front housing 330. A length of the guide pin 338 is shorter than adistance defined between outer limits of the guide pin openings 348 and352, which allows the guide pin 338 to move relative to the fronthousing 330 and the back housing 332.

FIG. 15 illustrates further components of the viewing device 12,including a fastener 364, a pliable member 366 and a barrier component368. The fastener 364 is used to secure the anchor piece 256 to thefront housing 330.

The pliable member 366 is secured in position between the barriercomponent 368 and the bionicle frame 334. When the nose piece 216 isinstalled, a rear surface of the stem 322 makes contact with the barriercomponent 368. The barrier component 368 is made of an electricallyinsulating material. The electrically insulating material of the barriercomponent 368 stops electric conductivity between a nose area of a userand the bionicle frame 334 as a means to protect against electric shockor the like. The barrier component 368 forms a seal between the nosepiece 216 and the bionicle frame 334 to prevent ingress of dirt into anarea 370 between the nose piece 216 and the bionicle frame 334.

When the user creates forces on the nose piece 216, such forces aretransferred through the barrier component 368 to the pliable member 366.The pliable member 366 is a springable member that is made of anelastomeric material. The elastic properties of the pliable member 366causes the pliable member 366 to compress and expand to absorb theforces and limit transfer of the forces to the bionicle frame 334.

While certain exemplary embodiments have been described and shown in theaccompanying drawings, it is to be understood that such embodiments aremerely illustrative and not restrictive of the current invention, andthat this invention is not restricted to the specific constructions andarrangements shown and described since modifications may occur to thoseordinarily skilled in the art.

1-35. (canceled)
 36. A visual perception device comprising: a first nosepiece that includes: a respective first locking component; a respectivenose pad having a respective nose bridge portion and respective firstand second nose tabs defining a respective inverted channel shape; arespective stem connecting the respective first locking component to therespective nose bridge portion; a respective first locking formation onthe respective first locking component; first and second viewingcomponents; a viewing device frame that includes at least a viewingdevice frame bridge connecting the first and second viewing componentsto one another; and a second locking formation on the viewing deviceframe bridge, the second locking formation and the respective firstlocking formation being first and second inter-engaging lockingformations respectively that are connectable to one another to removablymount the first nose piece to the viewing device frame bridge.
 37. Thedevice of claim 36, further comprising: a second nose piece thatincludes: a respective locking component; a respective nose pad having arespective nose bridge portion and respective first and second nose tabsdefining a respective inverted channel shape; a respective stemconnecting the respective first locking component to the respective nosebridge portion; and a respective first locking formation on therespective locking component, the second locking formation and therespective first locking formation being first and second inter-engaginglocking formations respectively that are connectable to one another toremovably mount the first nose piece to the viewing device frame bridge,wherein the stem of the second nose piece is longer than the stem of thefirst nose piece.
 38. The device of claim 36, wherein the respectivefirst locking formation includes: first and second lever armsrespectively connected to the respective stem; and first and second clipformations respectively on the first and second lever arms, wherein therespective clip formations are depressed by the second locking formationto bend the respective first and second lever arms towards one anotherwhen the clip formation is inserted into the second locking formationand the respective first and second lever arms expanding when therespective first and second clip formations exit the second lockingformation, wherein the respective first and second clip formationsresist disengagement of the respective first locking formation from thesecond locking formation.
 39. The device of claim 38, wherein eachrespective clip formation has an angular surface that engages with thelocking formation to depress the respective first and second clipformation towards one another to allow for insertion of the respectivefirst locking formation into the second locking formation.
 40. Thedevice of claim 39, wherein each respective clip formation has aninclined surface that engages with the second locking formation todepress the respective first and second clip formation towards oneanother to allow for removal of the respective first locking formationfrom the second locking formation.
 41. The device of claim 36, whereinthe respective first locking component includes: a respective forcetransfer member connected to the respective stem; and a respectiveelastic pad on the force transfer member, the respective elastic padengaging against a stopper portion of the viewing device and compressingwhile the respective first locking formation is inserted into the secondlocking formation.
 42. A method of visually perceiving light comprising:removably mounting a nose pad to a viewing device frame bridge; andpositioning the nose pad on a nose of a user, the nose pad having a nosebridge portion and first and second nose tabs defining an invertedchannel shape, the nose bridge portion forming part of a viewing deviceframe that includes the viewing device frame bridge connecting first andsecond viewing components. 43-71. (canceled)